Cochlear implants having MRI-compatible magnet apparatus and associated methods

Abstract

A cochlear implant is disclosed including a cochlear lead, an antenna, a stimulation processor, a magnet apparatus, associated with the antenna, including a case, a divider, and a plurality of magnetic material particles that are movable relative to one another within sub-volumes defined by the divider.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is the U.S. National Stage of PCT App. Ser. No. PCT / US2016 / 033944, filed May 24, 2016, which is a continuation-in-part of, and claims priority to, International Application No. PCT / US2015 / 033040, filed May 28, 2015, which is incorporated herein by reference in its entirety.BACKGROUND1. Field[0002]The present disclosure relates generally to the implantable portion of implantable cochlear stimulation (or “ICS”) systems.2. Description of the Related Art[0003]ICS systems are used to help the profoundly deaf perceive a sensation of sound by directly exciting the intact auditory nerve with controlled impulses of electrical current. Ambient sound pressure waves are picked up by an externally worn microphone and converted to electrical signals. The electrical signals, in turn, are processed by a sound processor, converted to a pulse sequence having varying pulse widths and / or amplitudes, and transmitted to an implanted receiver c...

AI Technical Summary

Benefits of technology

The text discusses the advantages of implants and systems that use magnets. It mentions that the magnet retainer in the housing is stronger with a square-shaped magnet than a circular magnet with the same dimensions. The smaller open area also reduces the likelihood of biofilm formation compared to larger circular openings. Additionally, the square magnet has more magnetic material and can be inserted through an elongate slot more easily. These technical effects make the implants and systems more effective and easier to use.

Problems solved by technology

Such magnets are not compatible with magnetic resonance imaging (“MRI”) systems.

The implant magnet produces a magnetic field M in a direction that is perpendicular to the patient's skin and parallel to the Z-axis of the implant magnet, and this magnetic field direction is not aligned with, and may be perpendicular to (as shown), the direction of the MRI magnetic field B. The misalignment of the interacting magnetic fields M and B is problematic for a number of reasons.

Nor will it generate a significant amount of torque on the magnet apparatus and associated cochlear implant.

The smaller open area defined by the elongate slot also reduces the likelihood of biofilm formation, as compared to larger circular openings.

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